1. Field of the Invention
The present invention relates to an electrophotographic recording apparatus of the type using a dry-process developing unit and, more particularly, to a device installed in a small-size, dry-process electrophotographic copier for replacing and supplying a single composition developer consisting of colored magnetic particles, or toner, or a dual composition developer which is a mixture of carrier and non-magnetic toner.
2. Discussion of the Background
In a dry-process developing unit of an electrophotographic copier, particularly one using the dual composition developer, the carrier of the developer undergoes fatigue after a long period of use and thereby losses the expected frictional charging effect. It is therefore necessary to replace the used developer, especially the carrier, with fresh developer from time to time. Heretofore, replacement of such a developer has exclusively been taken charge of by a serviceman and has required the steps of taking the developing unit out of the copier, removing the used developer by manipulating a special member or by bodily tilting the developing unit, and supplying a fresh developer into the empty developing unit. This not only causes the used and fresh developers to scattered but increases the service cost due to the awkward manual labor involved.
A prior art developing unit is known which includes at least two sections, i.e., a developing section and a developer supplying section, as disclosed in Japanese Patent Laid-Open Publication No. 56-114969/1981 by way of example. The developer supplying section is made up of a mechanism for mounting a toner cartridge, a toner agitating member, a toner supply roller and other various members. Therefore, the developing unit occupies a substantial portion of the space available in a copier and requires a large number of structural elements. Such is contradictory to the ever increasing demand for reduction in size and cost in the copier market.